Climate changes in California come into focus
Written by Mike Lee
San Diego Union Tribune
noon, Nov. 20, 2011
A Wilson’s warbler is measured during a study of how bird sizes have changed over recent decades. — Photo by PRBO Conservation Science
A spate of recent research offers new insight into how global warming is changing or could change California, from the mountains to the seashore, in both predictable and unusual ways.
The studies show that common trees are fading from their current ranges, premium wine grape varieties are under siege, marine creatures are shifting locales, the hub of the state’s water system faces increasing risks and — surprisingly — birds in the state are getting bigger as the weather warms.
Such reports are part of a larger effort to localize climate predictions, which often have been fuzzy at the regional level.
The potential for a more rapid pace of ecological change was underscored in October when U.S. Department of Energy data showed that global carbon dioxide emissions jumped by a record amount between 2009 and 2010. It was viewed by many as a sign that efforts to control greenhouse gases have stalled and climate-related impacts could be more severe than previously thought.
Well before that data was made public, scientists in San Diego County and elsewhere had forecast water shortages in the Southwest as the region becomes more arid, along with rising ocean levels that are leading seaside communities to rethink coastal development. Such projections prompted Gov. Jerry Brown to call a Dec. 15 conference in San Francisco to address “extreme climate risks and California’s future.”
“Worldwide we have seen an increase in volatile weather events that have had significant impact on global food supplies,” state agriculture chief Karen Ross said heading into her agency’s forum on the issue last week. “As one of the key growing regions in the United States, California must be prepared for effects of a changing climate and what this means for food production.”
Not everyone agrees that the warming climate is cause for alarm and some of them took Brown to task for believing “mad science.”
“Global temperatures are always rising or falling. They always have, and they always will,” said James Taylor, senior fellow for environmental policy at the nonprofit Heartland Institute, which advocates for free-market solutions to social problems.
He said people should be wary of scientific reports about climate change. “So long as these studies claim a global warming crisis, the funding will continue to flow,” he said.
While climate predictions are fraught with uncertainty, researchers are increasingly able to look backward for clues about how changes are playing out even as they try to gauge the future.
“The challenge is to use the long-term data we’ve been collecting to understand how, where and why these changes are occurring,” said Nat Seavy, a research director for PRBO Conservation Science on the Central Coast.
While changes aren’t necessarily bad, many could force people to revise their relationships to natural resources — for instance by using less water, scooting back from the seashore or choosing different plants to grow.
“Ecosystems are always changing at the landscape level, but normally the rate of change is too slow for humans to notice,” said Steven Running, a professor at the University of Montana and a co-author of a new study about how the climate is reshaping forests. “Now the rate of change is fast enough we can see it.”
Using remote-sensing technology over a span of four years, researchers discovered what they call a huge “migration” of trees across the western United States and Canada, driven by drought, insects and fire.
The defoliation from major epidemics of bark beetle infestation, such as these in these stands of lodgepole pine in British Columbia, reflects the challenges that tree species face across the West as the climate changes. — Oregon State University
“We can’t predict exactly which tree (species) will die or which one will take its place, but we can see the long-term trends and probabilities,” said Richard Waring, study co-author at Oregon State University. “The forests of our future are going to look quite different.”
Heat threatens Northern California’s signature crop, which relies on moderate temperatures in places like Napa Valley. While warming in recent decades has generally had a positive effect on wine grape production, a study released in June by Stanford scientists said the trends could soon go too far. They projected that the amount of land suitable for cultivating premium wine grapes could shrink 50 percent by 2040 as the temperatures rise and prime growing territory shifts to Oregon.
In this photo taken Thursday Sept. 23, 2010, Cabernet Sauvignon grapes hang on the vine at Silverado Vineyards in Napa, Calif. The recent triple-digit heat that rolled over parts of California answered the prayers of many winemakers, allowing them to start harvesting grapes, albeit a little later than usual. Many farmers are anywhere from 10 days to three weeks behind last year’s harvest in a nerve-racking race that now includes beating the cooler temperatures and rain that come with fall. But growers may be thanking Mother Nature soon enough: the dramatic growing season might bring one of the state's finest harvests in years and with that, French-style wines with lower-than-average alcohol. (AP Photo/Eric Risberg) — AP
Nowhere are climate changes more likely to affect large numbers of Californians than in the Sacramento-San Joaquin Bay Delta, which provides water for 25 million people and for crops valued at $36 billion per year.
The U.S. Geological Survey in November released what it called the first integrated assessment of how the delta region will respond to global warming. It was based on what the agency said were observed patterns of longer growing seasons, smaller snowpacks, higher sea levels and more extreme tides.
Sunrise peering through early morning tule fog in Suisun Bay, part of the Sacramento-San Joaquin River Delta that is expected to change significantly as the climate warms. . — Francis Parchaso/USGS
“Today’s extremes could become tomorrow’s norms,” they said.
Off California’s coast, increases in tropical Humboldt squid and decreases in salmon abundance suggest marine creatures are trying to adapt to altered conditions, said William Sydeman of the nonprofit Farallon Institute for Advanced Ecosystem Research in Petaluma and science adviser for the California Ocean Protection Council.
The Humboldt, or jumbo squid, has expanded its range in recent years to include the entire west coast of the United States. Jumbo squid are carnivorous marine invertebrates and have a lifespan of just 1-2 years. In that time, they can grow to four feet in length. — National Marine Fisheries Service
Scientists in Northern California found that birds’ wings have grown longer and birds are increasing in mass over the past 40 years.
Their discovery runs counter to an ecological rule of thumb that says animals tend to be larger at higher latitudes, in part to conserve body heat that allows them to survive the cold. Under this reasoning, some scientists have predicted that animals will get smaller as Earth warms.